Hello, I was in Costa Rica in June of 2004, Loved the above ground sights. Now for the diving, I did 10 dives while I was down there and spent 10 days there. The surge was 5 to 10 feet, the vis was 25 feet max and the dive shops were happy with that visibility. If you are looking for a reef to dive on, I did not see one, but they do have some very big fish and even bigger sharks. I got a very nice picture of a Black Tip Shark, I think he was around 8 to 9 feet long. I loved the turtles, seen a sea snake. The water Temps were 82 deg and the air temps were in the mid 80s. If I went again I would try the Atlantic side. It reminded me of Diving in California but the water temps were in the mid 80s.
Try and make it to Tamerindo (sp) at night. That was cool. The food was great all over Costa Rica. As for you Wife, I am sorry. I went with a local friend, when diving she shopped.